Rebuilding the 1937 and older pressure plate can be a little tricky. The early design (activated with a carbon throw out bearing under pressure) requires extra steps when being rebuilt. With the help of an older shop manual (see below) the final details can be successful.
The personal letter is from Richard Wright of Westtown, NY. He did not receive the necessary final touches in the rebuilding procedure and he made the final adjustments. Fortunately, the 1935 Chevrolet shop manual has a description of how to complete this procedure. The following letter, pictures and shop manual page should be of help in the rebuilding procedure. A more advanced pressure plate was introduced in 1938. A new diaphragm design then became a standard in Chevrolet for 30 years.
The “X” mark on the clutch cover should be lined up as near as is possible with the “X” mark on the flywheel. These “X” marks are balance marks.
Place clutch pilot tool, Fig.99 into position. This tool properly lines up to the disc so that when the transmission is assembled the splines on the main drive gear shaft will line up and enter easily the splines in the clutch disc.
Assemble the nine cap screws holding the clutch cover to the flywheel, tightening each one , one turn at a time until the cover is assembled into position. Remove the clutch disc aligning tool. Assemble throwout bearing sleeve.
CLUTCH LEVER HEIGHTS
It is very important that the clutch levers be of the same height to assure correct clutch operation. In addition to the clutch levers being the same height, the maximum run-out of the clutch throw-out bearing plate should not exceed .020″ when measured with an indicator guage placed on the clutch housing.
The checking and correcting may be done after the transmission and clutch throw-out collar have been removed.
To check run-out, place the indicator guage on the clutch housing through the transmission hole as shown in Fig 100. Set the dial guage at zero and check run-out while turning engine. If run-out exceeds .020″ the high lever plate should be shimmed-up by placing a shim under each side of the plate at the attaching bolts, which will result in dropping the high finger. Connecting rod shims with the ends trimmed may be used.
REPLACEMENT OF TRANSMISSION
These operations are just the reverse of the removal operations. The tool shown in Fig 101 can be used to hold the universal joint rings in position while assembling the nuts.
CLUTCH PEDAL ADJUSTMENT
There are two very important adjustments to the clutch pedal. The first is for obtaining the proper clearance between the clutch pedal and the floor board and the second for obtaining 1″ of the pedal travel before the clutch begins to disengage. These two adjustments compensate for wear of the clutch parts, and if these two operations are performed when necessary, long trouble free clutch operation can be expected.
To obtain 1/2″ clearance between the clutch pedal and the floor board, loosen nuts “A” and “B” in Fig 102 and move the pedal stop either forward or backward until the clutch pedal clears the floor board 1/2″
Below is a letter from Richard Wright of Westtown, NY.